Self-laying track



Spt. Z5, 1945. c. w. LEGUILLON 2,385,453

SELF-LAYING TRACK v Filed Aug. a, 1.942

M75/FLL Patented Sept. 25, 1945 afstand` sELFfLAYING TRACK Charles W- Leguillon. AkronfQhio, assigner te The B. F. Gdodrclr Company, New York, YQ.; a' corporation of New York l Application ,August s, 1942. serial No. 454.145.

19 Claims. (orcos-iol This invention relates to self-laying track for vehicles and isespecially useful inthe construction of flexible self-laying track ortractors, military tanks, and agricultural and excavating ve.- hicles having strands of flexible metal cable embedded in rubber for sustaining the tension load. with anchor driving bars, grousers, couplings, and other substantially rigidy parts of the track an.- chored to such cables.

In prior attempts to make the track open-ended or in detachable sections satisfactory anchorage has been a problem, especially where it has been attempted to anchor the cables by rigidly clamping them in place, difficulties having been experienced due to premature breaking of the cable strands by concentratedV and sudden stresses in tension and flexing stresses developed in the cables particularly in their regions in or near the position of attachment. It has appearedV that the severe forces causingv this failure have had the character of shock in their effect, as when the track has bumped obstructions or 'the driving teeth have engaged the crossbars suddenly, setting up waves of tension stress in the cables re sulting in concentrated shock stresses in or near the zones of anchorage ofthe cables. The present invention aims to overcome the foregoing and other diillculties and to provide an improved flexible track structure, especially of an open-ended or sectional construction.

The principal objects of the invention. are to avoid concentrated stresses, to damp out Or avoid concentrated shock stresses, to avoid premature breakage of the cable elements, to provide lonn gevity of structure, and to eliminate sharp bending of the cable. Further objects are tofprovide effectively for ,anchorage ofthe tension elements such that the track may be' madeseparable 'or Sectional, and to provide for convenience of at'- tachment and detachment.

These and other objects will appear from ,the following description and the accompanying drawing. I

Q f the drawing,

Fig. 1 is a side elevation. of a driving Wheel and a portion of a flexible track thereabcut constructed in accordance with and embodying the. invern tion. parts of the track beine brckenaway- Fig. 2 is ,a tread face view of the `track Q f Fis. 1.,

parts beine broken away to shew its construction- Fie. 3 is a sectional view thereof; teken on line s--a of Fig. 2. Fig. 4 is a detail view of one of theendless `tension elements.

Fig. `5 is a plan view of 'a portion of a track,

showing a modified form of the invention, parts being broken away to show theconstruction. Y

Fig. 6, is a sectional view of an end ofV one of the cable tension elements," taken online 6--6 of; Fig. 5. Fig. 7 vis a face view of a portion of a track, showing a further modification of the invention,` parts being broken away. i

Fig. 8 is adetail view of a cable and its flexible4 sleeve, parts being broken away. i

Referring to the drawing, and rst to the embodirnent illustrated in Figs. 1 to 4f the numeral l0 designates a driving wheel of a vehicle of' the self-laying track type', and the numeral I l-aflcxible track extendingthereabout'. 'The track; illus-` trated has a center-drive'and comprises exible driving bands I2", I3 of vulcanized rubber-like material spaced-apart laterally to clear the driving teeth I4 ofA the driving wheels. Stiff `crossbars I6 of metal extend crossewise `of the track'at regular intervalsand have removable wear plates I'IV secured thereto by bolts I8'. These wear plates engage the teeth lof the sprocket and 'maybe provided; vas shown, with overlapping guide anges I9, 20 for preventingl side sway of the track.

To facilitate removalandoverhaul of the track, the trackis preferably made opemendedforinade in sections having attheir ends coupling bars! l, 22- which take the place'of the crossebars i6 at' these positions whenc'oupled to each other. For

' coupling the coupling bars to each other, these are provided at their ends with overlapping'ears 23, 24 through which bolts 25 extend. The bolts I'8 also assist in holding the coupling barsin coupled relation.

For'sustaining the loadV under tension, tension` members extend through these flexible bands t2, I3 from one couplingbar toanotherand are secured 'to the .coupling bars and the cross-bars. As shown in Fig. 4', eachtension' memberis in the form of an endless link of cable spliced at 26 as by 'securing the ends of the cable within a sleeve, preferably by swaging or contraction of the sleeve. This splice is preferably located intermediate successive cross-bars'so as to be free'to adjus'titself in the rubber-like material. For securing the loopsA of thelink to'thecoupling bars 2l, 22., the bars are each formed withfa mortice 21 through the coupling bar in the direction of the tension members, vpins ZBextend across the mortice-at spaced-apart intervalsvvith their ends fixed to the coupling bars, and the loops of the tension members encompass thepins at each tension bar.

yTo vprevent breaking of the tension members due to concentrated stresses; especially *due Vtov periodic and shock tensioning and flexing ofthe protects the` cable from contact with the pin and the coupling bar, and stilliy but elastically supports it for a distance away from the coupling bar. The ends of the sleeves 30 may be extended different distances from the coupling bar, or staggered, so as not to terminate at a single plane of cross-section of thert'rack.. Due to the elasticity and extensibility of the flexible The flexible sleeves may be of increasing pitch or stretched somewhat at their outboard ends and rial which also enclose portions of the connectsleeve both longitudinal movements and bending of the sleeve are possible and friction between the sleeve and the cable is minimized while' at Y the same time periodic tension peaks due to shockstressing of the track when the cross-bars strike the sprockets and the ground,and to vibration of the track, are vcushioned or damped out, while the cable is iirmly supported against sharp bending adjacent the coupling bar.

VTo assist further in damping out vibrational stresses ofthe cables and to provide increased flexibility of the flexiblel sleeves at their-outer ends', these ends of the sleeves may be wound with increasing pitch yor stretched somewhat after winding as illustrated at 'T8 'in the modification of Fig-8, thereby feathering out their .support of the cables.

Thecables and the iiexible sleeves are preferably completely embedded in the rubber-like material of the'exible bands I2, I3 and the rubberrlike material extends about them within the mortice and is bonded to the metal cables, the sleeves, and the connecting and cross-bars preferably by a bond resulting from vulcanization of the rubber-like material in contact with the metal. The rubber-like material may also be forced'in betweenthe convolutions of the sleeve 3D and the cables to insulate them and resist abrasive wear. v

The tension members may be of any desired length andthe track may be made up of one or more track sections'joined together by the coupling bars at their ends. When a plurality of sections are employed, a damaged section may ,be removed and replacedv without discarding they entire track.

In the form ofthe invention shown 'in Figs. 5 and 6, the tension members 50 are open-ended lengths of metallic cable. Each end of each cable member has a yllexible tubular sleeve member 5I thereabout similar to theflexible sleeves previously described, and a ferrule 52 of metal having a counterbore 53 to receive one end ofI the flexible sleeve `member 5i is swaged or contracted about the end-of the cable.- The ferrule 52 is then secured in a bushing 54- having an Vinwardly directed llange 55`forming a shoulder for securing it against tension. An outwardly directed shoulder 56 is formed on the opposite end of the bushing for holding it against tension in a socket 5l of a coupling bar 58; .The-coupling bar is formed with a plurality of such sockets forsecuring a plurality of tension members inV spaced-apart relation with their axes; preferably in a single plane. The bushings 54 are formed with a bellmouth 59adjacent the ange 55 so as to permit limited bending of the cable 50 and sleeve 5|, and the sleeve 5I extends well beyond the bushing so as to support the -cable flexibly and resiliently against sharp bending.

ing bars 58 and cross-bars 62 as in the construction of Fig, 2

In the form of the invention shown in Fig. '7, coupling bars 1U, 'll are eachy formed with mortices such as 'l2 crossed by a row of pins 13. A single metallic cable .14 is looped back and forth alternately aboutrthe pins of coupling bars 'lil and 1| .to'provide a plurality of reaches of cable each formed with loops about the pins. Flexible 'sleeves 15, which may be of close-wound spring wire, encompass the cable where it extends about each pin to protect it from wear and extend along the cable beyond the connecting bar to protect the cable against localized stress and sharp bending, the extent of the ends of the sleeves being for different distances to reduce opportunity for undue localized stress to result. Cross-bars l5 are secured to the reaches of cables at spacedapart intervals along the track between the coupling bars, as by intervening rubber-like material bonded to the parts, and flexible bands l? of vulcanized rubber-'like material enclose the cable and portionsof the cross-bars and coupling bars. The free ends of the' sleeves may be of increased pitch or spaced coils to feather olT their support of the cables as in the structures Ypreviously described.

In the several forms of the invention the flexible metallic sleeves extend a substantial distance away from the stili coupling bars along reaches of the metallic cable to eliminate or reduce stress peaks caused by periodic and shock stressing and exing of the cables and also to limit localized bending of the cable abruptly, and the free ends of the flexible sleeves are preferably of open coils and stepped in extent. The sleeves are also embedded within vulcanized rubber-like material, The rubber-like material may extend as a nlm between the cable and the liexible sleeve and its elasticity permits relative movement of the metallic parts while preventing them from abrading each other, and the rubber-like material is preferably bonded to all the metal parts.

'Variations may be made without departing from the spirit of the invention as it is dei-ined by the following claims.

I claim:

`1. In a ilexible self-laying vehicle track having anchoring members and flexible` metallic cables extending therebetween and anchored thereto, the combination.. of ai flexible sleeve closely surrounding a cable at an anchoring position and extending from within the anchoring member along the cable with the end of the sleeve disposed beyond the member.

2, In a flexible self-laying vehicle track having anchoring members `and iiexible metallic cables extending therebetween and anchored thereto, the combination of a flexible sleeve surrounding a cable atan anchoring position and extending along the cable with the end of the sleeve disposed beyond the member, and flexible vulcanized rubber-like material surrounding at least a portion' of said cable and said sleeve and extending therebetween.

. 3. A flexible self-laying vehicle track comprising anchoring members, flexible metallic cable links having looped connections with said members, and a flexible sleeve closely surrounding each cable at its looped portion with its ends extending in the same direction along the reaches of the link beyond the member.

4. A flexible self-laying vehicle track comprising anchoring members, flexible metallic cable links having looped connections with said members, a exible sleeve surrounding each cable at its looped portion with its ends extending along the reaches of the cable beyond the member, and flexible vulcanized rubber-like material surrounding a portion of said cable and said sleeve and extending therebetween.

5. A flexible self-laying vehicle track comprising a plurality of cross-members, flexible cables extending from one cross-member to another, and a flexible sleeve closely surrounding a portion of a cable at a cross-member, said sleeve comprising a tube of close-wound spring wire.

6. A flexible self-laying vehicle track comprising a plurality of cross-members, flexible cables extending from one cross-member to another, and a flexible sleeve surrounding a portion of a cable at a cross-member, said sleeve comprising a tube of spring wire wound helically in close coils throughout a part of its extent and of open coils therebeyond at the end of the sleeve remote from the cross-member.

7. A flexible self-laying vehicle track comprising parallel reaches of cable in spaced-apart relation, a cross-member secured to said reaches, flexible metallic sleeves surrounding individual cable reaches at said member, and a body of rubber surrounding said cable reaches and said sleeves, said sleeves extending different distances from said member along different reaches of cable.

8. A flexible self-laying vehicle track comprising a plurality of cross-members, flexible reaches of cable extending from one cross-member to another, a tubular flexible sleeve surrounding a portion of a cable reach at a cross-member, and a body of rubber enclosing the cable reach, the sleeve, and at least a portion of the cross-member, and extending between the sleeve and the cable.

9. A flexible self-laying vehicle track comprising a plurality of cross-members, a flexible cable extending between said cross-members and looped thereabout with its direction completely reversed, and a flexible tubular sleeve surrounding a looped portion of said cable at one of said cross-members.

10. A flexible self-laying vehicle track compr1sing a plurality of cross-members, a link of ilexible cableextending between cross-members and having loops engaging the cross-members, and a looped flexible metal sleeve surrounding the cable at each loop of the cable.

11. A flexible self-laying vehicle track comprising a looped flexible tension member extending lengthwise of said track, a member engaging a loop of said tension member, and a flexible sleeve surrounding said tension member between the tension member and the member engaging it at the looped portion.

l2. A flexible self-laying vehicle track comprising a flexible tension member extending lengthwise of said track, a member engaging a portion 0f said tension member, and a ilexible wire sleeve closely surrounding a portion of said tension member at the position of engagement.

13. A flexible self-laying vehicle track comprising a flexible tension member extending length- Wise of said track, a member engaging a portion of said tension member, and a flexible sleeve surrounding a portion of said tension member at the position of engagement, the ends of said sleeve extending different distances from the first said member.

14. In a flexible self-laying vehicle track having reaches of cable in spaced-apart relation, and a member secured to a plurality of said reaches, means for protecting said cable reaches comprising a flexible wire sleeve adapted to be secured at said member and to extend along the cable reaches from said member.

15. In a flexible self-laying vehicle track having reaches of cable in spaced-apart relation, and a stiff metallic member secured to a plurality of said reaches, means for protecting said cable reaches comprising a flexible metallic sleeve closely encompassing a cable reach and secured at said metallic member and to extend along the cable reach to a position beyond said member, said sleeve being of close-wound spring wire.

16. In a flexible self-laying vehicle track having reaches of cable in spaced-apart relation, and a stiff metallic member secured to a plurality of said reaches, means for protecting said cable reaches comprising a flexible metallic sleeve adapted to be secured at said metallic member and to extend along a cable reach beyond said member, said sleeve being of helically-Wound spring wire of close coils at its position of attachment and open coils at its free end.

17. A flexible self-laying vehicle track comprising a flexible tension member extending lengthwise of said track, a stiff metallic member engaging a portion of said tension member, and a flexible tubular sleeve surrounding a portion of said tension member at the position of engagement, said tension member comprising a metal cable and said sleeve comprising wire closely coiled about said cable at said stiff metallic member and terminating beyond the latter.

18. A flexible self-laying vehicle track comprising a plurality of track sections, coupling members at the ends of a section, a flexible tension member extending through said section from one coupling member to another and secured thereto, and a flexible tubular sleeve extending from a coupling member along said tension member to a position beyond the coupling member, said sleeve comprising a helically coiled element closely encompassing said tension member.

.19. A track section for a flexible self-laying vehicle track having a plurality of track sections, said section comprising stiff metallic coupling members at the ends of the section, said sections having sockets, bushings seated in said sockets, a flexible metal cable having its ends secured in said bushings at each coupling member, and a flexible tubular sleeve surrounding a portion of said cable with one end thereof secured at a bush- CHARLES W. LEGUILLON. 

